Watching stars at night on dock when suddenly this beam of light from above me, took me by surprise. It was as bright as a "strobe" light. Flashed directly into my face. Lasted approximately 20 seconds, then it seemed to , for lack of a better word, "return" to what appeared to be a transparent object. The UFO traveled in a S-shaped motion forward , moving fast and then slow. Distance to UFO from myself , well, up there where satellites roam. Observed object until treetops blocked my view.